Let's make a data table to understand how the forces and torques have to add to zero
Question:
Let's make a data table to understand how the forces and torques have to add to zero so we don't get any rotating, collapsing bridges.
Force | L.a.d. | pos. or neg. | Torque, |
RA= | 0 | + | 0 |
FB=10kN | 1 | - | -10kN |
RC= | 4 | + | 4RC |
So add the torques in that column of the data table and set them equal to 0:
Solve the above equation for Rc and put that value both in the table and on the diagram. Then use that value in the equation below to solve for RA:
Put your values for RA and Rc both in the data table and on the diagram. Then answer these questions:
Question #1: Why does the lever arm distance for the torque resulting from the reactant force at point C have a value of 4?
Question #2: Why does the lever arm distance for the force (FB) due to the weight of the truck have a value of 1?
Question #3: Why is the torque due to the reactant force at point A equal to 0?
Question #4: Why is FB negative?
Question #5: Why is RC positive?
Income Tax Fundamentals 2013
ISBN: 9781285586618
31st Edition
Authors: Gerald E. Whittenburg, Martha Altus Buller, Steven L Gill